The purpose of this research is to determine the change in mutant frequency s well as the spectra of molecular rearrangements within a somatic gene, hprt of fetal T-lymphocytes exposed to genotoxic metabolites as a result of materna exposure to active and passive cigarette smoke. Cord blood samples will be obtained from the placenta of term infants. A formal questionnaire on medi l and socioeconomic history will be taken on each mother.